Nanoparticle compositions and methods for enhancing lead-acid batteries

ABSTRACT

This disclosure relates to compositions and methods for improving the performance of batteries, such as lead-acid batteries, including reviving or rejuvenating a partially or totally dead battery, by adding an amount of nonionic, ground state metal nanoparticles to the electrolyte of the battery, and optionally recharging the battery by applying a voltage. The metal nanoparticles may be gold and coral-shaped and are added to provide a concentration within the electrolyte of 100 ppb to 2 ppm or more (e.g., up to 5 ppm, 10 ppm, 25 ppm, 50 ppm, or 100 ppm). The metal nanoparticles may be added to battery electrode paste applied to the electrodes to enhance newly manufactured or remanufactured batteries.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/202,078, filed Nov. 27, 2018, which claims the benefit ofU.S. Prov. App. No. 62/591,540, filed Nov. 28, 2017, and U.S. Prov. App.No. 62/674,416, filed May 21, 2018, which are incorporated by referencein their entirety.

BACKGROUND

Lead-acid batteries are the most common type of rechargeable battery inthe field of motor vehicle batteries. Although lead-acid batteries havelow energy densities compared to newer battery technologies, theirability to provide relatively large surge currents make them effectivefor powering automobile starter motors. Lead-acid batteries are alsorelatively inexpensive compared to newer battery technologies, makingthem attractive choices for providing rechargeable power even incircumstances outside the motor vehicle field.

A lead-acid battery in a charged state includes a “negative electrode”made of ground state lead (Pb), a “positive electrode” made of leaddioxide (PbO₂), and an electrolyte containing aqueous sulfuric acid(H₂SO₄). During discharge, lead from the negative electrode is oxidizedby bisulfate ions from the sulfuric acid to form lead ions (Pb²⁺), eachcorresponding to a sulfate ion from the sulfuric acid to form partiallysoluble lead sulfate (PbSO₄), with the reaction producing 2 electrons(e⁻). In the other half redox reaction, lead dioxide (Pb⁴⁺) from thepositive electrode is reduced by protons (H⁺) from the sulfuric acid toform lead ions (Pb²⁺), each corresponding to a sulfate ion from thesulfuric acid to form partially soluble lead sulfate. Water is alsoproduced, forming a more dilute sulfuric acid electrolyte in adischarged state. Over time and/or when the battery is more fullydischarged, solid lead sulfate can form and precipitate onto theelectrode plates.

When a newer battery is recharged, solid lead sulfate formed on thepositive electrode plates during discharge can easily revert back toground state lead (Pb²⁺ is reduced to Pb at the positive electrodeplates), solid lead sulfate formed on the negative electrode platesduring discharge can easily revert back to lead oxide (Pb²⁺ is oxidizedto Pb⁴⁺ at the negative electrode plates), and sulfuric acid is producedfrom protons (H⁺) and released sulfate ions (SO₄ ²⁻) to form theelectrolyte. However, lead-acid batteries will, over time, lose theability to be recharged as a result of excessive sulfation at and/ordegradation of the electrode plates. Through multiple cycles of chargeand discharge, some of the lead sulfate on the electrode plates willbegin to form a more stable, crystalline form covering the plates. Overtime, progressive buildup of solid lead sulfate on the plates increasesinternal resistance of the battery cell, and less and less of thesurface area of the plates is available for supplying current andaccepting a charge. Eventually, so much of the battery capacity isreduced that the battery is considered “dead” and must be replaced.

BRIEF SUMMARY

In some embodiments, a method of rejuvenating and/or improving theperformance of a lead-acid battery and/or enhancing the performance of anew battery includes: (1) providing a lead-acid battery; (2) adding anamount of nonionic, ground state metal nanoparticles to the electrolytesolution of the battery to yield a concentration of nanoparticles in theelectrolyte of least about 100 ppb and up to about 100 ppm, 50 ppm, 25ppm, 10 ppm, 5 ppm, or 2 ppm; and (3) the nonionic, ground state metalnanoparticles rejuvenating and/or improving the performance of thelead-acid battery.

In the case of dead battery, or a fully or partially discharged battery,the method may also include recharging the battery to regenerate lead(Pb) at the “positive” electrode plate (“anode” during discharge,“cathode” during recharge), lead dioxide (PbO₂) at the “negative”electrode plate (“cathode” during discharge, “anode” during recharge),and sufficient sulfuric acid in the electrolyte solution. It is believedthat by including nanoparticles in the electrolyte, resistance throughthe lead sulfate deposited on the electrode plates is decreased. Thisfacilitates an increased number of charge-discharge cycles, therebyincreasing total service life of the battery.

In some embodiments, the metal nanoparticles are added so as to bringthe concentration of nanoparticles within the electrolyte to aconcentration of about 100 ppb to about 2 ppm. The treated battery mayshow one or more of increased fully charged resting voltage, increasedpartially discharged voltage, increased cranking amps, increased coldcranking amps, and increased reserve capacity. Nanoparticleconcentration levels above 2 ppm (e.g., up to about 100 ppm, 50 ppm, 25ppm, 10 ppm, or 5 ppm) may also be utilized where appropriate, althougheffective performance enhancement was typically found when usingconcentration levels within the foregoing ranges without the need toincur additional material costs at higher concentration levels.

It has also been found that the disclosed metal nanoparticles added toor included with the electrolyte end up migrating to the paste on thebattery electrodes. Battery electrode paste is typically applied to theelectrodes during manufacture or remanufacture of batteries and is madeby mixing lead (II) oxide (PbO) with sulfuric acid and water to formlead sulfate compounds, such as PbO.PbSO₄ (monobasic lead sulfate),2PbO.PbSO₄ (dibasic lead sulfate), 3PbO.PbSO₄ (tribasic lead sulfate),and 4PbO.PbSO₄ (tetrabasic lead sulfate). In some cases, a binder, suchas a polymer binder, can be added to the paste. It will be readilyappreciated that since nanoparticles added to the electrolyte willmigrate to the paste on the electrodes, it can be advantageous duringmanufacture or remanufacture of batteries to add the disclosednanoparticles directly to the battery electrode paste in addition to oras an alternative to adding the nanoparticles to the electrolyte.

Some embodiments are directed to a lead-acid battery having effectiveresistance to degradation from the buildup of crystalline PbSO₄ onelectrode surfaces. The battery includes a “positive electrode” (cathodeduring discharge, anode during recharge), a “negative electrode” (anodeduring discharge, cathode during recharge), and an electrolyte. Aplurality of nonionic, ground-state metal nanoparticles are alsoincluded and are dispersed within the electrolyte at a concentration ofat least about 100 ppb (e.g., up to about 2 ppm, 5 ppm, 10 ppm, 25 ppm,50 ppm, or 100 ppm).

In preferred method or device embodiments, the metal nanoparticlesinclude gold nanoparticles. Some embodiments may additionally oralternatively include metal nanoparticles formed as alloys of anycombination of gold, silver, platinum, and first row transition metals.The metal nanoparticles may be spherical and/or coral-shapednanoparticles. In the case of coral-shaped nanoparticles, the particleshave a non-uniform cross section, a smooth surface, and a globularstructure formed by multiple, non-linear strands joined together withoutright angles, with no edges or corners resulting from joining ofseparate planes.

To enable the nanoparticles to effectively position themselves withinthe battery plate, the particles preferably have a mean length ordiameter of less than about 100 nm. This size allows the nanoparticlesto move to positions sufficiently deep within the layer of PbSO₄ buildupat an electrode plate to provide their beneficialelectropotential-modulating effects. The particles, for example, mayhave a mean length or diameter ranging from about 25 nm to about 80 nm.

The smooth, non-angular shape of the nanoparticles described herein alsoallow for this beneficial positioning at plate grain boundariessufficiently deep within the layer of PbSO₄ buildup. In contrast, theangular, hedron-like shapes of conventional nanoparticles, includingthose formed using a chemical synthesis process, prevent this desiredpositioning because these nanoparticles tend to get caught atsuperficial depths of the crystalline PbSO₄ buildup layer.

Nanoparticles may be formed through a laser-ablation process, incontrast to a chemical synthesis process, to produce nanoparticles thathave a smooth surface with no external bond angles or edges, as opposedto a hedron-like or crystalline shape nanoparticles made by conventionalchemical processes. In some embodiments, the nanoparticles have a narrowsize distribution wherein at least about 99% of the nanoparticles arewithin 30%, 20%, or 10% of the mean length or diameter.

Additional features and advantages will be set forth in part in thedescription that follows, and in part will be obvious from thedescription, or may be learned by practice of the embodiments disclosedherein. It is to be understood that both the foregoing brief summary andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the embodiments disclosed herein or asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only illustrated embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings, in which:

FIGS. 1 and 2 illustrate a lead-acid battery cell in acharged/discharging and discharged state, respectively;

FIG. 3 illustrates a lead-acid battery cell showing buildup ofcrystallized pre-precipitated PbSO₄ on electrode surfaces, which can atleast partially block electrons or ions from passing to or from theelectrodes;

FIG. 4 illustrates a lead-acid battery cell having an amount ofnon-ionic, ground state, metal nanoparticles dispersed within theelectrolyte for improving electron transport across the layer ofcrystallized PbSO₄ buildup at the anode during a recharge cycle;

FIGS. 5A-5C show transmission electron microscope (TEM) images ofcoral-shaped nanoparticles useful for improving the performance of alead-acid battery;

FIGS. 6A-6C show TEM images of exemplary spherical-shaped metalnanoparticles (i.e., that have no surface edges or external bond angles)useful for improving the performance of a lead-acid battery, thenanoparticles showing substantially uniform size and narrow particlesize distribution, smooth surface morphology, and solid metal cores;

FIGS. 7A-7D show TEM images of various non-spherical nanoparticles(i.e., that have surface edges and external bond angles) made accordingto conventional chemical synthesis methods;

FIGS. 8A and 8B show images of a battery plate from an untreatedlead-acid battery;

FIGS. 9A and 9B show images of a battery plate from a lead-acid batterytreated with Au coral-shaped nanoparticles at a concentration in theelectrolyte of 200 ppb;

FIGS. 10A and 10B show additional images of an untreated lead-acidbattery;

FIGS. 11A and 11B show the surface of a plate from a battery treatedwith Au coral-shaped nanoparticles at a concentration in the electrolyteof 2 ppm;

FIGS. 12A and 12B show the results of a comparative performance testbetween an untreated battery and a battery treated with Au coral-shapednanoparticles; and

FIGS. 13A through 13E illustrate the results of cyclic voltammetry (CV)testing of untreated and nanoparticle treated batteries.

DETAILED DESCRIPTION Introduction

Disclosed herein are nanoparticle compositions and related methods forimproving the performance of lead-acid batteries. In particular,embodiments described herein may be utilized to provide increasedvoltage (which corresponds to increased current and power) and/orextended battery life. In at least some embodiments, a batteryconsidered to be “dead” may be revived by adding an effective amount ofthe nanoparticles described herein to the electrolyte of the battery,optionally in combination with a recharge cycle.

As used herein, a “dead” battery may be a battery that is unable toreceive and/or hold a charge for a sufficiently long time and/or providesufficient amperage for its intended purpose. As used herein,“rejuvenating” a dead battery means bringing it from a dead state to astate where the battery is able to receive and/or hold a charge for asufficiently long time and provide sufficient amperage for its intendedpurpose. More particular means for determining battery state aredescribed in more detail below.

Battery condition may be checked using a suitable testing method asknown in the art, such as checking the fully charged resting voltage ofthe battery, subjecting the battery to a load test, or determining thespecific gravity (e.g., using a hydrometer) of the electrolyte, whichdecreases as the battery is discharged and/or is lower than optimal in adead or “dying” battery even when “fully charged.” For purposes of thisdisclosure, such batteries may still be in a working condition, but mayhave deteriorated to less than the recommended or desired capacityand/or voltage. For example, for a typical six-cell motor vehiclelead-acid battery, a fully charged resting voltage of less than 12.6 V(i.e., about 2.1 V per cell) may indicate that the battery is in need ofreplacement or repair even if still capable of starting the motorvehicle. A fully charged resting voltage of about 12 V or less is aneven greater indication that the battery is in need of replacement.

A load test may be an even better means of determining the state of thebattery, as the load test will determine the actual deliverable amperageof the battery. Suitable load tests include measuring the cranking amps(CS) and/or cold cranking amps (CCA) of the battery. These tests measurethe discharge load in amperes that a fully charged battery can deliverfor 30 seconds while maintaining terminal voltage equal or greater than1.20 V per cell. The test is performed at 0° F./−18° C. (for CCA) or 32°F./0° C. (for regular CA). For purposes of this disclosure, a batterymay be considered to be “dead” when the CA and/or CCA of the batteryfalls to or below about 85%, 80%, 75%, 70%, 65%, or 50% of the battery'sinitial rating (e.g., listed manufacturer rating or initial new batteryrating).

The reserve capacity of the battery may be used as an additional oralternative indicator of battery status. A reserve capacity testmeasures the duration the battery can maintain a constant 25 amperesdischarge, at 80° F. (27° C.) before being discharged down to 10.5 V.For purposes of this disclosure, a battery may be considered to be“dead” when the reserve capacity of the battery falls to or below about85%, 80%, 75%, 70%, 65%, or 50% of the battery's initial rating (e.g.,listed manufacturer rating or initial new battery rating).

It has now been found that adding an amount of nonionic, ground statemetal nanoparticles to the electrolyte of a lead-acid battery mayimprove the performance of the lead-acid battery and/or may bring thebattery from a depleted or “dead” sate to a usable state. Surprisingly,it has been found that these effects may be achieved using relativelylow concentrations of nanoparticles in the electrolyte, on the order ofabout 100 ppb to about 2 ppm (or up to about 5 ppm, 10 ppm, 25 ppm, 50ppm, or 100 ppm).

Little to no difference was seen in the effects from a 200 ppbconcentration to a 2 ppm concentration, indicating that beneficialeffects may be achieved even at the lower end of these ranges. Forexample, as compared to a level of 2 ppm, substantially similar effectsmay be achieved at a level of about 200 ppb to 1 ppm, or about 200 ppbto 750 ppb, or about 200 ppb to 500 ppb. Using less nanoparticlematerial can significantly reduce costs. Nonetheless, amounts of thedisclosed nanoparticles up to about 5 ppm, 10 ppm, 25 ppm, 50 ppm, or100 ppm are substantially less than typical amounts of othernanoparticles used in prior art systems. For example, conventionalnanoparticle battery treatments may add metal nanoparticles to theelectrolyte at concentrations on the order of 0.5% or more by weight(i.e., 5000 ppm). Even if effective in improving battery performance,such high levels of nanoparticles represent a significant cost and maynegatively impact the electrolyte.

Overview of Lead-Acid Battery Rejuvenation or Enhancement

FIG. 1 illustrates a typical lead-acid battery cell in acharged/actively discharging state. At the negative electrode plate, theelectrode consists essentially of ground state lead (Pb) and/or includesa lead coating, while at the positive electrode plate, the electrodeconsists essentially of lead dioxide (PbO₂) and/or includes a PbO₂coating. An electrolyte, typically of aqueous sulfuric acid (H₂SO₄), isin contact with the positive and negative electrode plates. Lead-acidbatteries including other electrolytes, such as citric acid, are alsoincluded within the scope of the present disclosure.

In a typical sulfuric acid electrolyte, the sulfuric acid provideshydrogen ions and soluble bisulfate ions, which are both consumed byredox reactions during discharge and, alternatively, are produced byredox reactions during recharge. When the circuit is closed, theoxidation reaction at the negative plate generates electrons andhydrogen ions, and the lead electrode begins to convert to PbSO₄. Thereaction at the negative plate is shown below:Pb(s)+HSO₄ ⁻(aq)→PbSO₄(s)+H⁺(aq)+2e ⁻

At the positive plate, the electrons and hydrogen ions combine withoxygen from the PbO₂ to form water, while the PbO₂ electrode begins toconvert to PbSO₄. The reaction at the positive plate is shown below:PbO₂(s)+HSO₄ ⁻(aq)+3H⁺(aq)+2e ⁻→PbSO₄(s)+2H₂O(l)Because more protons are consumed than are produced during discharge,the electrolyte becomes less acidic, and thus more dilute, as water isgenerated at the positive plate and the cell moves toward the dischargedstate.

FIG. 2 illustrates the battery cell in the discharged state. As shown,both electrodes will move contain a greater proportion of PbSO₄.Recharging the battery involves applying sufficient voltage to theelectrolyte and run the circuit in the reverse of that shown in FIG. 1 ,thereby bringing the negative plate toward a greater proportion of lead(Pb), the positive plate toward a greater proportion of PbO₂, andcausing the electrolyte to become more concentrated with sulfuric acid.

FIG. 3 schematically illustrates buildup of a crystalline PbSO₄ on theelectrode plates. In a newer battery, solid PbSO₄ formed on theelectrode plates is more amorphous and more easily reverts back to lead,lead dioxide, and sulfuric acid as a voltage is applied and the batteryis recharged. Through multiple cycles of charge and discharge, however,some of the PbSO₄ will not be recombined into the electrolyte and willbegin to form a more stable, crystalline form on the plates. Over time,sulfation buildup reduces the ability of electrons and ions to pass toand from the working electrode surfaces, increasing internal resistanceof the battery cell and decreasing its capacity. In addition, thebuildup of this stable crystalline form of PbSO₄ can eventually causethe plate to bend, making the battery take on the bulging shapeassociated with dead batteries.

FIG. 4 schematically illustrates a plurality of nonionic, ground statemetal nanoparticles added to the electrolyte of the battery cell.Without wishing to be bound to any particular theory, it is postulatedthat a portion of the nanoparticles are able to move into the layer ofcrystalline PbSO₄ buildup and maintain open regions of the electrodeplate where the buildup of crystalline PbSO₄ is prevented. Thenanoparticles within the bulk electrolyte and within the layer ofcrystalline PbSO₄ buildup are able to improve electron transport throughor across the layer of the crystalline PbSO₄ buildup and to the workingsurface of the electrode plate.

Likewise, it is theorized that during recharging, the nanoparticlespotentiate the release of SO₄ ²⁻ ions from solid PbSO₄ to reform H₂SO₄in the electrolyte. It is believed that the nanoparticles are able tobring about the dissolution of even stable, crystalline forms of PbSO₄responsible for detrimental buildup and battery degradation. Thus, it istheorized that the nanoparticles can both: (1) aid in electron transportthrough or across a crystalline PbSO₄ layer, and (2) aid in slowing orpreventing the formation, or promoting the disassociation, ofcrystalline PbSO₄ deposits over time.

It has also been found that the disclosed metal nanoparticles added toor included with the electrolyte end up migrating to the paste on thebattery electrodes. Battery electrode paste is typically applied to theelectrodes during manufacture or remanufacture of batteries and is madeby mixing lead (II) oxide (PbO) with sulfuric acid and water to formlead sulfate compounds, such as PbO.PbSO₄ (monobasic lead sulfate),2PbO.PbSO₄ (dibasic lead sulfate), 3PbO.PbSO₄ (tribasic lead sulfate),and 4PbO.PbSO₄ (tetrabasic lead sulfate). In some cases, a binder, suchas a polymer binder, can be added to the paste. It will be readilyappreciated that since nanoparticles added to the electrolyte willmigrate to the paste on the electrodes, it can be advantageous duringmanufacture or remanufacture of batteries to add the disclosednanoparticles directly to the battery electrode paste in addition to oras an alternative to adding the nanoparticles to the electrolyte.

Batteries that were manufactured with or treated with the nanoparticlesdescribed herein were also surprisingly and unexpectedly found to chargeat much faster rates compared to untreated batteries. In one example, abattery that was expected to take about 14 hours to fully charge wasable to reach a fully charged state after about 6 hours afternanoparticles were included within the electrolyte. Treated batteriesmay therefore reduce the charging time by 10% or more, by 20% or more,by 30% or more, by 40% or more, by 50% or more, or up to about 60%.

Preferred embodiments utilize coral-shaped metal nanoparticles, whichare described in more detail below. As used herein, the term“coral-shaped nanoparticles” refers to nanoparticles that have anon-uniform cross section, a smooth surface, and a globular structureformed by multiple, non-linear strands joined together without rightangle and with no edges or corners resulting from joining of separateplanes. This is in contrast to nanoparticles made through a conventionalchemical synthesis method, which yields particles having a hedron-likeshape with crystalline faces and edges, and which can agglomerate toform “flower-shaped” particles.

Other embodiments may additionally or alternatively includespherical-shaped nanoparticles. As used herein, the spherical-shapednanoparticles are not the same as the hedron-like, multi-edged particlesformed through a conventional chemical synthesis method. Rather,spherical-shaped nanoparticles are formed through a laser-ablationprocess that results in a smooth surface without edges.

The relative smoothness of the surfaces of the nanoparticles describedherein beneficially enables the formation of very stable nanoparticlesolutions, even without the use of a stabilizing agent. For example,such smooth nanoparticles may be stored in solution (e.g., at roomtemperature) for months or even years (e.g., 1 to 2 years, up to 3 yearsor more, up to 5 years or more) with little to no agglomeration ordegradation in particle size distribution.

The smooth, non-angular shape of the nanoparticles described herein alsoallow for beneficial positioning of the nanoparticles at plate grainboundaries that are sufficiently deep within the layer of PbSO₄ buildup.In contrast, the angular, hedron-like shapes of conventionalnanoparticles, including those formed using a chemical synthesisprocess, prevent this desired positioning because these nanoparticlestend to get caught at superficial depths of the crystalline PbSO₄buildup layer.

Preferred embodiments utilize gold nanoparticles, though other materialsmay additionally or alternatively be utilized as well. For example, someembodiments may additionally or alternatively include nanoparticlesformed from alloys of gold, silver, platinum, first row transitionmetals, or combinations thereof. Other exemplary metals are describedbelow.

The carrier for the nanoparticles is preferably suitable for additioninto the electrolyte of a lead-acid battery. In preferred embodiments,the carrier is water and/or aqueous sulfuric acid without any additionalstabilizing agents so as not to disrupt the reactivity of theelectrolyte.

The nanoparticle compositions may be added to a lead-acid battery havinga liquid or solid (e.g., gel) electrolyte. Nanoparticle compositionsdescribed herein may be added to dead or underperforming batteries torejuvenate and/or improve the performance of the batteries. Nanoparticlecompositions described herein may also be added to new or properlyfunctioning batteries to enhance capacity and/or prophylactically extendthe usable life of the battery.

The addition of nanoparticles to the electrolyte of a lead-acid batterymay improve one or more of fully charged resting voltage, partiallydischarged voltage, cranking amps, cold cranking amps, reserve capacity,and/or other battery capacity and/or power measures. In one example,average cell voltage of a motor vehicle lead-acid battery was shown toincrease from about 2.1 V or about 2.4 V to about 2.6 V (e.g., anincrease of about 8 to 25%) after addition of the disclosednanoparticles to the electrolyte.

Nanoparticle Configurations

In some embodiments, the metal nanoparticles may comprise or consistessentially of nonionic, ground state metal nanoparticles. Examplesinclude coral-shaped metal nanoparticles, spherical-shaped metalnanoparticles, or a blend of spherical-shaped metal nanoparticles andcoral-shaped metal nanoparticles.

In some embodiments, nonionic metal nanoparticles useful for makingnanoparticle compositions comprise coral-shaped nanoparticles (see FIGS.5A-5C). The term “coral-shaped metal nanoparticles” refers tonanoparticles that are made from one or more metals, preferablynonionic, ground state metals having a non-uniform cross section and aglobular structure formed by multiple, non-linear strands joinedtogether without right angles. Similar to spherical-shapednanoparticles, coral-shaped nanoparticles may have only internal bondangles and no external edges or bond angles. In this way, coral-shapednanoparticles can be highly resistant to ionization, highly stable, andhighly resistance to agglomeration. Such coral-shaped nanoparticles canexhibit a high ξ-potential, which permits the coral-shaped nanoparticlesto remain dispersed within a polar solvent without a surfactant, whichis a surprising and unexpected result.

In some embodiments, coral-shaped nanoparticles can have lengths rangingfrom about 15 nm to about 100 nm, or about 20 nm to about 90 nm, orabout 25 nm to about 80 nm, or about 30 nm to about 75 nm, or about 40nm to about 70 nm. In some embodiments, coral-shaped nanoparticles canhave a particle size distribution such that at least 99% of thenanoparticles have a length within 30% of the mean length, or within 20%of the mean length, or within 10% of the mean length. In someembodiments, coral-shaped nanoparticles can have a ξ-potential of atleast 10 mV, preferably at least about 15 mV, more preferably at leastabout 20 mV, even more preferably at least about 25 mV, and mostpreferably at least about 30 mV.

Examples of methods and systems for manufacturing coral-shapednanoparticles through a laser-ablation process are disclosed in U.S.Pat. No. 9,919,363, which is incorporated herein by reference.

In some embodiments, metal nanoparticles useful for making nanoparticlecompositions may also comprise spherical nanoparticles instead of, or inaddition to, coral-shaped nanoparticles. FIGS. 6A-6C show transmissionelectron microscope (TEM) images of spherical-shaped nanoparticlesutilized in embodiments of the present disclosure. FIG. 6A shows agold/silver alloy nanoparticle (90% silver and 10% gold by molarity).FIG. 6B shows two spherical nanoparticles side by side to visuallyillustrate size similarity. FIG. 6C shows a surface of a metalnanoparticle showing the smooth and edgeless surface morphology.

Spherical-shaped metal nanoparticles preferably have solid cores. Theterm “spherical-shaped metal nanoparticles” refers to nanoparticles thatare made from one or more metals, preferably nonionic, ground statemetals, having only internal bond angles and no external edges or bondangles. In this way, the spherical nanoparticles are highly resistant toionization, highly stable, and highly resistance to agglomeration. Suchnanoparticles can exhibit a high ξ-potential, which permits thespherical nanoparticles to remain dispersed within a polar solventwithout a surfactant, which is a surprising and unexpected result.

In some embodiments, spherical-shaped metal nanoparticles can have adiameter of about 40 nm or less, about 35 nm or less, about 30 nm orless, about 25 nm or less, about 20 nm or less, about 15 nm or less,about 10 nm or less, about 7.5 nm or less, or about 5 nm or less.Spherical-shaped nanoparticles can have a mean diameter of about 3 nm toabout 20 nm, or about 4 nm to about 15 nm.

In some embodiments, spherical-shaped nanoparticles can have a particlesize distribution such that at least 99% of the nanoparticles have adiameter within 30% of the mean diameter of the nanoparticles, or within20% of the mean diameter, or within 10% of the mean diameter. In someembodiments, spherical-shaped nanoparticles can have a mean particlesize and at least 99% of the nanoparticles have a particle size that iswithin ±3 nm of the mean diameter, ±2 nm of the mean diameter, or ±1 nmof the mean diameter. In some embodiments, spherical-shapednanoparticles can have a ξ-potential (measured as an absolute value) ofat least 10 mV, preferably at least about 15 mV, more preferably atleast about 20 mV, even more preferably at least about 25 mV, and mostpreferably at least about 30 mV.

Examples of methods and systems for manufacturing spherical-shapednanoparticles through a laser-ablation process are disclosed in U.S.Pat. No. 9,849,512, incorporated herein by this reference.

The metal nanoparticles, including coral-shaped and/or spherical-shapednanoparticles, may comprise any desired metal, mixture of metals, ormetal alloy, including at least one of gold, silver, platinum,palladium, rhodium, osmium, ruthenium, rhodium, rhenium, molybdenum,copper, iron, nickel, tin, beryllium, cobalt, antimony, chromium,manganese, zirconium, tin, zinc, tungsten, titanium, vanadium,lanthanum, cerium, heterogeneous mixtures thereof, or alloys thereof.

In contrast to coral-shaped and spherical-shaped nanoparticles as usedherein, FIGS. 7A-7D show TEM images of nanoparticles made according tovarious chemical synthesis methods. As shown, the nanoparticles formedusing these various chemical synthesis methods tend to exhibit aclustered, crystalline, or hedron-like shape rather than a truespherical shape with round and smooth surfaces. For example, FIG. 7Ashows silver nanoparticles formed using a common trisodium citratemethod. The nanoparticles are clustered and have a relatively broad sizedistribution. FIG. 7B shows another set of silver nanoparticles(available from American Biotech Labs, LLC) formed using anotherchemical synthesis method and showing rough surface morphologies withmany edges. FIG. 7C shows a gold nanoparticle having a hedron shape asopposed to a truly spherical shape. FIG. 7D shows a set of silvernanoparticles (sold under the trade name MesoSilver), which haverelatively smoother surface morphologies but are understood to be shellsof silver formed over a non-metallic seed material.

Multi-Component Nanoparticle Compositions

In some embodiments, coral-shaped metal nanoparticles can be usedtogether with spherical-shaped metal nanoparticles. In general,spherical-shaped metal nanoparticles can be smaller than coral-shapedmetal nanoparticles and in this way can provide very high surface areafor catalyzing desired reactions or providing other desired benefits. Onthe other hand, the generally larger coral-shaped nanoparticles canexhibit higher surface area per unit mass compared to spherical-shapednanoparticles because coral-shaped nanoparticles have internal spacesand surfaces rather than a solid core and only an external surface. Insome cases, providing nanoparticle compositions containing bothcoral-shaped and spherical-shaped nanoparticles can provide synergisticresults. For example, coral-shaped nanoparticles can help carry and/orpotentiate the activity of spherical-shaped nanoparticles in addition toproviding their own unique benefits.

In some embodiments, a nanoparticle composition may comprise (1) a firstset of metal nanoparticles having a specific particle size and particlesize distribution, (2) and second set of metal nanoparticles having aspecific particle size and particle size distribution, and (3) acarrier.

EXAMPLES

In the following Examples, a series of lead-acid batteries givendifferent electrolyte treatments were tested for their ability to accepta charge and for various discharge performance indicators. Batterieswere charged using a standard industrial battery charger, and weredischarged using a DC to DC heater fan accessory. The various additivestested were added according to standard practices for maintainingappropriate electrolyte density. ICP-OES (inductively coupled plasmaoptical emission spectrometry) and EDS (scanning electron microscope andenergy-dispersive X-ray spectroscopy) were used to verify nanoparticlelocation and concentration.

Throughout the Examples, the additive labeled or referred to as“Attostat Au” represents an additive including coral-shaped, goldnanoparticle compositions of the present disclosure (with size of about25 nm). The nanoparticles of the additive labeled as “Synth Au” arestandard, chemically synthesized gold nanoparticles with a hedron shape.The additive labeled “Cadsulf” is a commercially available cadmiumsulfide-based electrolyte product marketed as a battery electrolyteenhancer. Each treatment was provided in a 40 ml volume. The 40 mlvolume was diluted by approximately 10× when mixed with the electrolytewithin the battery.

Example 1

Batteries in a chemically “dead” condition were unable to take a charge.The batteries were treated with 40 ml of an electrolyte treatmentcomposition having 2 ppm Attostat Au in water. Results are shown inTable 1. As shown, the electrolyte treatment was able to revive the“dead” batteries and restore effective battery performance.

TABLE 1 Performance of Revived Batteries (Treated with 40 ml Attostat Auat 2 ppm concentration) Charge Capacity Battery Model (Amp-hours)Everstart Marine 24 MS 50.8 Unlabeled automobile battery 49.2

Example 2

Dead batteries for a small rider mower (battery model: Everstart U1R7)were unable to take a charge. The batteries were treated with variouselectrolyte treatments to determine the ability to recover thebatteries. Results are shown in Table 2 below. In Table 2, the “FirstDischarge” column provides data related to the first discharge of thebattery following treatment and initial charging of the battery.Batteries were subsequently charged again and then retested to providethe data in the “Second Discharge” column.

TABLE 2 Charge Capacity (Amp hours) of Dead Batteries FollowingTreatment First Second Additive (40 ml) Discharge Discharge Attostat Au2 ppm 9.2 14.7 Synth Au 2 ppm 9.2 12.4 Cadsulf 6.6 10.2

As shown, the battery treated with Attostat Au nanoparticles showed thebest results, particularly during the second discharge. It is theorizedthat while the chemically synthesized Au treatment gave positive initialresults, the superior ability of the nanoparticles of the Attostat Autreatment to remain stable in solution better sustains positive effectsover time.

Example 3

Several new batteries (battery model: Autocraft 65-2) were subjected toa series of discharge and charge cycles prior to treatment of theelectrolyte. Following treatment, the batteries were again subjected toa series of discharge and charge cycles. Charge capacities of thebatteries were measured to determine whether the treatment would have aneffect over successive discharge/charge cycles. For each treatment,successive discharge/charge cycles were conducted (up to three) untilperformance was shown to (1) improve or be unaffected, or (2) decreaseby more than 50%. Results are shown in Table 3.

TABLE 3 Charge Capacity (Amp hours) of New Batteries Following TreatmentFirst Second Third Additive (40 ml) Discharge Discharge DischargeAttostat Au 2 ppm 42.1 50.8 Synth Au 2 ppm 52.2 48.7 47.3 Cadsulf 48.212.4

As shown, the battery treated with Attostat Au saw improved performancebetween successive discharge/charge cycles, whereas the battery treatedwith chemically synthesized Au saw steady degradation of performanceover successive discharge/charge cycles. The battery treated with theCadmium Sulfide product saw significant degradation after the firstpost-treatment discharge.

In the above results, the trend from one discharge/charge cycle to thenext is likely more important to battery longevity and performance thanthe initial charge capacity immediately following treatment. It istheorized that while the chemically synthesized Au treatment gavepositive initial results, the superior ability of the nanoparticles ofthe Attostat Au treatment to remain stable in solution better sustainspositive effects over time.

Example 4

Images of a plate from an untreated lead-acid battery were obtained andare shown in FIGS. 8A and 8B. FIG. 8A shows an edge section of PbSO₄buildup on the electrode plate. FIG. 8B is a magnified view of the samePbSO₄ buildup of FIG. 8A. The edge view of FIG. 8B illustrates therelatively large crystalline structure of the PbSO₄ buildup. Suchcrystals resist disassociation during battery recharging and can lead todegradation of battery performance over time.

As a comparison, images of a plate from a similar lead-acid battery thathad been treated with 200 ppb Au coral-shaped nanoparticles wereobtained and are shown in FIGS. 9A and 9B. From the vantage of FIG. 9A,several darker spots where “craters” have been formed within the PbSO₄layer are visible.

Without being bound to any particular theory, it is believed that theadded nanoparticles associate with grain boundaries at the plate surfaceand alter the electropotential differences between grain boundaries. Thecraters result because one or more nanoparticles at a crater siteprevent excessive PbSO₄ buildup during battery discharge, whereas PbSO₄continues to be deposited at other areas surrounding the crater. Thenanoparticles thus function to maintain a greater surface area ofexposed underlying Pb or PbO₂, which better maintains the ability foreffective ion transfer to the electrode plate.

FIG. 9B illustrates a magnified view of a crater such as shown in FIG.9A. As confirmed by EDS, the lighter sections of the image (i.e., thesections surrounding the crater) have a higher proportion of oxygen thanthe darker sections (i.e., the sections deeper within the crater),indicating that the crater exposes more of the underlying Pb electrodesurface relative to the higher levels of PbSO₄ surrounding the crater.

Example 5

Images of a plate from an untreated lead-acid battery were obtained andare shown in FIGS. 10A and 10B (the visible cutout of FIG. 10A wasintentionally applied for cross-sectional visualization). The relativelylarge size of PbSO₄ crystals are visible in the magnified view of FIG.10B.

As a comparison, FIGS. 11A and 11B show the surface of a plate from abattery treated with 2 ppm Au coral-shaped nanoparticles. An edge of thecrater shown in FIG. 11A is shown in magnified view in FIG. 11B. Thegrain sizes of the PbSO₄ layer shown on the visualized edge, which areon the order of 10 to 30 nm, are much smaller than the large crystallinestructures shown in FIG. 10B. The treated plates are thereforebenefitted in that 1) the formed craters provide better effective accessto the underlying electrode surface and less resistance to ion transfer,and 2) at least some of the PbSO₄ formed on the electrode plate is in amore-preferred smaller grain form that more readily disassociates ascompared to larger crystals.

Example 6

A comparative test was performed comparing the performance of newlead-acid batteries (Napa brand, size 7565 batteries), one of which wasuntreated and one of which was treated by adding gold coral-shapednanoparticles to the electrolyte to a concentration of between 200 ppbto 2 ppm. Discharge/charge cycling performance data was measuredaccording to the standard test procedure BCIOS-06 Rev 10-2012, Section3.

Testing was carried out according to the following:

Test Initiation:

At the completion of pretest conditioning, record on-charge voltage,charging rate, temperature, and specific gravity. When all requirementsof capacity test conditions were met, the discharge was initiated within24 hours.

Discharge Cycle:

Mono-blocks and/or battery packs of the test circuit were discharged atthe selected constant current discharge rate until the terminal voltagereached 1.75 volts per cell. The discharge time and capacity wasrecorded in minutes or amp-hours and the % of Rated Capacity wascalculated by dividing the discharge capacity by the published ratedcapacity for that discharge rate. These data points were plotted on acycle life curve with either Discharge Capacity or % of Rated Capacityplotted against Cycle Number.

Charge Cycle:

Mono-blocks and/or battery packs of the test circuit were recharged perthe battery manufacturer's charging recommendations.

Rest Periods:

Following the charge cycle as above, an optional rest period not toexceed eight hours was provided in order to allow the mono-blocks and/orbattery packs of the test circuit to cool such that the temperaturerequirements were maintained.

Electrolyte Level & Specific Gravity

In those batteries with electrolyte access, the electrolyte levels weremaintained by periodic water additions in accordance with manufacturer'sinstructions or such that the level of electrolyte was maintained at aminimum of 6 mm (0.25 in.) above the top of the separators.

Results:

The comparative testing results are shown in FIGS. 12A and 12B. In FIG.12A, “AttoWattHrs” and “AttoAmpHrs” represent the performance metrics ofthe treated battery, while “NonWattHrs” and “NonAmpHrs” represent theperformance metrics of the non-treated battery. As shown, both batteriesprovided similar performance with respect to both watt hours and amphours until about cycle 22. After cycle 22, the performance of thenon-treated battery began to degrade much faster than the treatedbattery.

At cycle 30, the treated battery was accidentally overcharged, causingsome of the electrolyte to boil and causing the relatively abrupt dip inperformance. The accidental overcharge was a result of the treatedbattery reaching a charged state much faster than expected. While thefaster charging capability of the treated battery was a surprisingbenefit of the treatment, the accidental overcharge resulted in anunfortunate dip in performance relative to its expected potential.Nevertheless, despite the overcharging incident, the treated batterycontinued to provide better performance in both watt hours and amp hoursas compared to the nontreated battery as can clearly be shown in theplot of FIG. 12A.

FIG. 12B relates to the same performance data and shows the differencein watt hours between the treated and non-treated battery at each cycle.As shown, as the number of cycles continued, the difference inperformance grew increasingly greater.

Example 7

Samples of the electrolyte from tested batteries, as well as CV testcell, were processed through ICP-OES to determine concentrations. Theoriginal amount of Attostat Au concentration of the Au nanomaterial inelectrolyte measured to 0.15-0.2 mg/L. The concentration measure withICP-OES did not show significant fallout or absorption with readingsshowing that concentrations were maintained at 0.15-0.20 mg/L at the endof experiments. This occurred even though the testing environment hadsignificantly more variables than a table top in-situ test.

Example 8

Based upon published research and reference literature on lead acidcyclic voltammetry (CV) testing, the following experiment was performed.Sample rate of 25 samples per second, Minimum Voltage of −0.74V and aMaximum of 1.8V, rate of 0.065 V/sec were programmed into an IORodeostat potentiostat using a Gamray EuroCell as the vessel. A Calomelprobe was chosen for reference with the understanding that temperaturecontrol would be required for accurate readings. A Buchi Rotovap bathwas used with ethylene glycol as the bath media and kept at 30 C(measured), which the EuroCell was immersed for the experiment. Thecounting electrode was a solid pure lead cylinder 1.25 cm in diameterand 1.25 cm in length threaded onto a stainless steel rod in the centerof the EuroCell. The working electrode is the same foil that was used inthe SEM imaging and cut to allow insertion to an exterior port of theEuroCell. ICP-OES was used to verify the concentrations of Attostat Auwhich were then diluted according to volumes in the EuroCell and in someworking electrode preparation baths, to achieve a 0.2 mg/L (200 ppb)levels. Also to mitigate noise in the system a 0.01 uF capacitor waslinked between the counting electrode and the calomel referenceelectrode as per instruction from the manufacturer of the IO Rodeostatpotentiostat system.

Analysis Software and Computational Programming:

The data was collected with libraries provided by the manufacturer ofthe IORodeo Potentiostat and implemented in Python scripting language ona Linux OS system. The files collected required further review andanalysis techniques that were performed and programmed in Matlab usingthe Savitsky-Golay filtering technique to acquire the most accuratecurves possible from the raw data provided by the IORodeostat. The datawas finally reviewed in Origins software with the CV application toprovide information on the curves of the CV and extrapolation of peakheights, positions and integrations under the CV curves. Excel was usedto plot comparisons for review.

Preparation of Electrode Surfaces:

A 10 g/L citric acid solution was used to clean off existing oxidelayers of the working electrode lead foil before immediately beingintroduced to an oxidizing solution of 3% H₂O₂ with and without AttostatAu present at a concentration of 0.2 mg/L (200 ppb). Although in theliterature the use of hydrogen peroxide was not used for creating anoxidation layer on the lead working electrode, this proved efficaciouswithout potentially adding contaminants. No H₂O₂ was used in theelectrolyte of the CV cell and care was taken to only introduce dryelectrodes after lead oxide formation was completed. For each CV testthe electrodes were treated as so:

-   -   1 and 2. Electrode in 3% H₂O₂ for 2 hours    -   3. Electrode in 3% H₂O₂ and 200 ppb Attostat Au for 2 hours    -   4. Electrode in 3% H₂O₂ and 200 ppb Attostat Au for 24 hours.        CV Experiment 1:

A baseline was performed and monitored via the computer interface to thepotentiostat. The counting and working electrode along with thereference calomel electrode were placed in the EuroCell along with 1.27kg/L sulfuric acid to the port levels of the Cell. CV runs wereperformed until the data graphs showed equilibrium. Some finalequilibrium level runs were recorded.

CV Experiment 2:

Without changing the electrodes or electrolyte from Experiment 1, asolution of Attostat Au by volume to create a 0.2 mg/L concentration ofnanoparticles was introduced to the electrolyte and allowed to diffuseinto an even mixture. The program was again run until equilibrium wasdetected in the graphs, then individual runs recorded for analysis.

CV Experiment 3:

CV Experiment 3 Without changing the electrolyte in the EuroCell theworking and counting electrodes were removed. The counting electrode wasresurfaced with 1200 grit sand paper and citric acid washes. A newelectrode treated in a bath of H₂O₂ for 2 hours with the additionalpresence of 0.2 mg/L of Attostat Au was created. Noted that the rapidcoating of lead oxide was not seen showing an inhibiting effect of thepresence of the Attostat Au in electrode preparation. The counting andworking electrode were placed in the Eurocell in same positions asprevious experiments and CV cycles run until equilibrium was met.Individual runs for analysis were taken after equilibrium was reached.

CV Experiment 4:

Due to the inhibiting factor of the Attostat Au in the H₂O₂ oxide layerprocess, another working electrode was produced in the H₂O₂ and 0.2 mg/LAttostat Au bath for a period of 24 hours. The counting electrode wasresurfaced and cleaned, then introduced back into the EuroCell with theworking electrode having more of an oxide coating then the 2 hourtreatment in Experiment 3. CV cycles were run until equilibrium wasachieved. Individual runs for analysis were taken after equilibrium wasobserved in the multi run graphs.

Results:

FIG. 13A shows the forward cyclic voltammetry comparisons of Experiments1-4 at equilibrium. The potential at which the current peaks areobserved are significantly different between electrolyte with andwithout Attostat. The area under the peaks which correlates to amountsof oxide produced is largest in the 24-hour treated working electrodewith Attostat Au in electrolyte but with a lower current peak then thatof the baseline. Also the potential difference between beginning andending of the peaks is greater than the baseline peaks.

FIG. 13B shows the backward CV comparisons of Experiments 1-4 atequilibrium. In relation to baseline the potential at which the valleysstart are earlier in the 2, 3, and 4 experiments. The electrolyte onlyaddition of Attostat Au possesses a valley that is earlier than thebaseline which appears to diminish to almost unnoticeable in theelectrolyte and working electrode surface treatments with Attostat Au.As these experiments were designed around published settings it isunknown if the curves may be at more negative potentials than thebaseline and require modification of the test to include that change inthe cycle minimum voltage setting.

FIG. 13C-13E illustrate the raw CV graphs for equilibrium point.

The full CV forward and backward curves are significantly different inthe lead acid baseline and the Attostat Au presence in the electrolyteand electrodes. However, the presence in the electrolyte appears to havethe immediate effect in change. The αPbO₂ peak in the baseline is veryvisible, wherein the Attostat presence does not appear to have aprevalent αPbO₂ peek. Also, the potentials of activity are differentbetween the baseline and the Attostat Au presence. Anodic and cathodicmaximum peak currents are less in the Attostat Au presence. Theintegrated area under the peaks are similar. Also, the number of runs toreach equilibrium was different between the experiments, and are asfollows:

-   -   Experiment 2: 12 rubs to Equilibrium    -   Experiment 3: 10 runs to Equilibrium    -   Experiment 4: 29 runs to Equilibrium

The benefits of Attostat Au addition to lead acid batteries has directimpact for many energy storage uses. It is also noteworthy that severallead acid batteries that were ready for recycle due to storage capacityloss were brought back to useable, and in some cases, factory newspecifications for capacity.

Example 9

Any of the foregoing examples is modified to use nonionic, ground statemetal nanoparticles comprising at least one metal instead of or inaddition to gold.

Example 10

Any of the foregoing examples is modified to use an amount of nonionic,ground state metal nanoparticles so that the electrolyte solution of thebattery contains 5 ppm of the metal nanoparticles. Using this amount ofmetal nanoparticles is at least as effective as in previous Examples inrejuvenating and/or improving performance of a lead-acid battery.

Example 11

Any of the foregoing examples is modified to use an amount of nonionic,ground state metal nanoparticles so that the electrolyte solution of thebattery contains 10 ppm of the metal nanoparticles. Using this amount ofmetal nanoparticles is at least as effective as in previous Examples inrejuvenating and/or improving performance of a lead-acid battery.

Example 12

Any of the foregoing examples is modified to use an amount of nonionic,ground state metal nanoparticles so that the electrolyte solution of thebattery contains 25 ppm of the metal nanoparticles. Using this amount ofmetal nanoparticles is at least as effective as in previous Examples inrejuvenating and/or improving performance of a lead-acid battery.

Example 13

Any of the foregoing examples is modified to use an amount of nonionic,ground state metal nanoparticles so that the electrolyte solution of thebattery contains 50 ppm of the metal nanoparticles. Using this amount ofmetal nanoparticles is at least as effective as in previous Examples inrejuvenating and/or improving performance of a lead-acid battery.

Example 14

Any of the foregoing examples is modified to use an amount of nonionic,ground state metal nanoparticles so that the electrolyte solution of thebattery contains 100 ppm of the metal nanoparticles. Using this amountof metal nanoparticles is at least as effective as in previous Examplesin rejuvenating and/or improving performance of a lead-acid battery.

Example 15

Any of the foregoing examples is modified to use nonionic, ground statemetal nanoparticles in electrolytes of other types of batteries, whichare not lead-acid batteries.

Example 16

An electrode paste for application to battery electrodes duringmanufacture or remanufacture is modified by adding Attostat Au to thepaste. The battery electrode paste is made by mixing lead (II) oxide(PbO) with sulfuric acid and water to form lead sulfate compounds,including one or more of PbO.PbSO₄ (monobasic lead sulfate), 2PbO.PbSO₄(dibasic lead sulfate), 3PbO.PbSO₄ (tribasic lead sulfate), and4PbO.PbSO₄ (tetrabasic lead sulfate). A binder, such as a polymerbinder, can be added to the paste. Because Attostat Au is essentiallyinert and unreactorive, it can be added to the paste before, during orafter forming the lead sulfate compounds.

The paste is used in the manufacture or remanufacture of a battery andprovides the same or greater enhanced effects as described above in theprevious Examples.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

The invention claimed is:
 1. A method of rejuvenating and/or improvingperformance of a battery having an electrolyte solution, comprising:providing a battery having an electrolyte solution; adding an amount ofnonionic, ground state gold nanoparticles to the electrolyte solution soas to bring the concentration of the gold nanoparticles within theelectrolyte solution to at least 100 ppb and up to 100 ppm, wherein thegold nanoparticles are formed by laser ablation so as to have a smoothsurface with no external bond angles or edges; and the nonionic, groundstate gold nanoparticles rejuvenating or improving the performance ofthe battery.
 2. The method of claim 1, wherein the addition of thenanoparticles to the electrolyte solution increases a fully chargedresting voltage of the battery as compared to a fully charged restingvoltage of the battery prior to addition of the nanoparticles.
 3. Themethod of claim 1, wherein the addition of the nanoparticles to theelectrolyte solution increases a cranking amps or cold cranking ampsrating of the battery as compared to a cranking amps or cold crankingamps rating of the battery prior to addition of the nanoparticles. 4.The method of claim 1, wherein the addition of the nanoparticles to theelectrolyte solution increases a reserve capacity of the battery ascompared to a reserve capacity of the battery prior to addition of thenanoparticles.
 5. The method of claim 1, wherein an average cell voltageof the battery is increased to 2.6 V and/or is increased by 8 to 25%. 6.The method of claim 1, wherein the nanoparticles comprise coral-shapednanoparticles having lengths ranging from 15 nm to 100 nm, wherein thecoral-shaped nanoparticles have a non-uniform cross section, a smoothsurface, and a globular structure formed by multiple, non-linear strandsjoined together without right angles, with no edges or corners resultingfrom joining of separate planes.
 7. The method of claim 1, wherein thenanoparticles comprise spherical-shaped nanoparticles having a meandiameter of 3 nm to 20 nm, wherein the spherical-shaped nanoparticleshave no surface edges or external bond angles.
 8. The method of claim 1,wherein the nanoparticles have a concentration within the electrolytesolution of at least 100 ppb and up to 50 ppm.
 9. The method of claim 1,wherein the nanoparticles have a concentration within the electrolytesolution of at least 100 ppb and up to 25 ppm.
 10. The method of claim1, wherein the nanoparticles have a concentration within the electrolytesolution of at least 100 ppb and up to 10 ppm.
 11. The method of claim1, wherein the nanoparticles have a concentration within the electrolytesolution of at least 100 ppb and up to 5 ppm.
 12. The method of claim 1,further comprising recharging the lead-acid battery by applying avoltage.
 13. The method of claim 1, wherein the gold nanoparticles areadded using a composition consisting of the gold nanoparticles and atleast one of water or sulfuric acid.
 14. A lead-acid battery havingimproved performance, comprising: a positive electrode; a negativeelectrode; an electrolyte in electrical contact with the positive andnegative electrodes; and a plurality of nonionic gold nanoparticlesdispersed within the electrolyte at a concentration of at least 100 ppband up to 100 ppm, wherein the gold nanoparticles are formed by laserablation so as to have a smooth surface with no external bond angles oredges.
 15. The lead-acid battery of claim 14, wherein the nanoparticleshave a concentration within the electrolyte of at least 100 ppb and upto 25 ppm.
 16. The method of claim 14, wherein the electrolyte consistsof the gold nanoparticles and at least one of water or sulfuric acid,and optionally lead sulfate.
 17. A method of manufacturing an enhancedbattery electrode paste comprising: providing a battery electrode pasteformed from lead oxide, sulfuric acid, and water to form one or morelead sulfate compounds selected from PbO.PbSO₄ (monobasic lead sulfate),2PbO.PbSO₄ (dibasic lead sulfate), 3PbO.PbSO₄ (tribasic lead sulfate),and 4PbO.PbSO₄ (tetrabasic lead sulfate); and adding nonionic, groundstate gold nanoparticles to yield the enhanced battery electrode paste,wherein the gold nanoparticles are formed by laser ablation so as tohave a smooth surface with no external bond angles or edges.
 18. Themethod of claim 17, wherein the nonionic, ground state goldnanoparticles are added before, during, or after forming the one or morelead sulfate compounds.